New main-group and early transition-metal complexes of mono-pendant arm triazacyclononane ligands

Journal article

A family of new Group 3, Group 13 and early transition metal complexes of the previously described monoanionic, pendant arm macrocyclic ligands L a, L b and L c are described where HL a = (3,5-dimethyl-2-hydroxybenzyl)-4,7-diisopropyl-1,4,7-triazacyclononane 1a, HL b = (3,5-di-tert-butyl-2-hydroxybenzyl)-4,7-diisopropyl-1,4,7-triazacyclonon ane 1b, and HL c = (3,5-di-tert-butyl-2-hydroxybenzyl)-4,7-dimethyl-1,4,7-triazacyclononane 1c. The ligand precusors 1a-c are quantitatively converted to the corresponding new potassium salts KL a, KL b and KL c 2a-c by reaction with potassium hydride in tetrahydrofuran (THF). An improved synthesis of HL c 1c is also reported. Reaction of KL a-c with Group 13 metal salts MCl 3 (M = Al, Ga or In) gives monomeric derivatives [M(κ 4-L a-c)Cl 2] 3-5 in good yields. The crystal structure of [In(κ 4-L b)Cl 2] 5b has been determined and confirms the six-coordinate, cis-dichloride structures proposed for these complexes. Reaction of KL a-c with TlCl 3 gives the asymmetric, binuclear analogues [Tl(κ 4-L a-c)Cl 2] 2 6a-c. Reaction of [Al(κ 4-L c)Cl 2] 3c with AlCl 3 gives the unstable, five-coordinate cation [Al(κ 4-L c)Cl] + as its AlCl 4- salt 8c. Reaction of KL a-c with MCl 3, (M = Sc or Y) or [MCl 3(THF) 3] (M = Ti, V, Cr) in THF gives generally good yields of the Group 3 cis-dichloride derivatives [M(κ 4-L 1a-c)Cl 2] (M = Sc 8a-c or Y 9b,c) and the early transition metal analogues [M(κ 4-L b,c)Cl 2] (M = Ti 10b,c, V 11b,c or Cr 12b,c). Reaction of HL 1a-c with TlOEt yields the monomeric, four-coordinate thallium(I) derivatives [Tl(κ 4-L 1a-c)] 13a-c as confirmed by the X-ray crystal structures of 13b and 13c. © The Royal Society of Chemistry 2001.

Authors: Bylikin, S; Robson, D; Male, N; Rees, L; Mountford, P

• Publication status: Published
• Journal: JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS
• Issue: 2
• Pages: 170-180
• Publication date: 2001-01-01
• DOI: 10.1039/b008267n
• ISSN: 1472-7773
• Language: English